unexpected behaviour of 'this' keyword

Question

var name="globalName"
var age=12

var person={name:"abc",
age:6,
callMe: function ()
{
return (`Name is:${this.name} Age is:${this.age}`)
}

}

console.log(person.callMe()) // expected & actual output =>Name is:abc Age is:6

//calling a function
var p1=person.callMe()
console.log(p1) // expected & actual output =>Name is:abc Age is:6

//assign refrence of function
var p2=person.callMe
console.log(p2()) // Name is:undefined Age is:undefined

Answer 1

https://code.sololearn.com/WZ6tO3CKqEl4/?ref=app